Connect a chromecast to a wifi network

[kkhanh]

Hi,

First of all, thank you @rithvikvibhu for your work.

I would like to know if you or anyone else has made any progress regarding the "enc_passwd" parameter.

We have built a solution around the chromecast and to speed up the configuration, my company is willing to reward 750€ the person who can successfully connect a chromecast to a WPA2 network using the /connect_wifi endpoint or any workaround. There will also be an additionnal reward if you can connect the chromecast to a Google account and change the screen saver settings (hide weather, hide time, change background screen through Google photos)

You can contact us at [email protected]

Regards,

[rithvikvibhu]

Hey, @thorleifjaocbsen figured out the connect wifi endpoint including the password encryption here: https://github.com/rithvikvibhu/GHLocalApi/issues/68

I kinda missed (forgot about) that issue and was marked closed by the bot before it was added to the docs - will get to it soon.

I don't have a chromecast to check the Google account linking, but feel free to rename this issue to mention the reward and I'll leave it open here in case anyone is interested.

[kkhanh]

Hi, Thanks for the help. We can confirm it is working. We are still interested in linking a chromecast to a Google account and a way to change the settings listed above.

[kkhanh]

I forgot to mention you need to call /setup/save_wifi with this data {"keep_hotspot_until_connected": true} otherwise it will fail.

[interfect]

I had trouble applying the API docs without the Curl command examples, so I've turned these learnings into a Bash script that can set up your Chromecast for you: https://gist.github.com/interfect/5f68381d55658d334e2bc4619d796476

Download it, make it executable, get a connection over which you can talk to the Chromecast by IP, and then do something like:

CHROMECAST_IP=192.168.0.100 WIFI_SSID="foobar" WIFI_PASSWORD="hackme" ./castanet.sh

Not sure how to connect it to a Google account or tinker with the screensaver though.

[interfect]

Reports of my script working may have been greatly exaggerated.

I can get the device to join the wifi network, and somehow the first time I did it I got it to actually save the network details and reconnect after a reboot. But then it eventually dropped off the network the next day, and now, when I have it hooked up to the TV, when I tell it to join the network it joins and displays a "Connecting to" screen that won't go away on its own. I can talk to it over wifi and even cast to it, but even if it is playing something, it decides after a couple minutes that the wifi network is Bad Actually and disconnects and forgets it.

I think it is waiting for something else that the app would usually do, but I don't know what that is or how to emulate it. It isn't just "cast something to the device". My best theory right now is that it might be "set_eureka_info", since that's something I manually called on the day I wrote the script and not since, but even that didn't get it to stay on the network indefinitely since it eventually left the next day.

[interfect]

OK I read @kkhanh's comment again and noticed the save_wifi endpoint was mentioned, not connect_wifi. And according to http://blog.brokennetwork.ca/2019/05/setting-up-google-chromecast-without.html?m=1 that call is both essential and not documented in this repo. I will try adding it to the script (and maybe the repo?).

[leo5593]

Hello,

@interfect Thank you very much for the script with the save_wifi, i was missing this part to finalize the connection to an open network.

I still have trouble with secured network. Nodejs is not happy with crypto.constants.RSA_PKCS1_PADDING.

internal/crypto/cipher.js:63
    return method(data, format, type, passphrase, buffer, padding, oaepHash,
           ^

Error: error:0408F08D:rsa routines:pkey_rsa_ctrl:invalid padding mode
    at Object.publicEncrypt (internal/crypto/cipher.js:63:12)
    at Object.<anonymous> (/home/nico/Dev/Chromecast/enckey.js:21:30)
    at Module._compile (internal/modules/cjs/loader.js:999:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1027:10)
    at Module.load (internal/modules/cjs/loader.js:863:32)
    at Function.Module._load (internal/modules/cjs/loader.js:708:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:60:12)
    at internal/main/run_main_module.js:17:47 {
  opensslErrorStack: [
    'error:06089093:digital envelope routines:EVP_PKEY_CTX_ctrl:command not supported'
  ],
  library: 'rsa routines',
  function: 'pkey_rsa_ctrl',
  reason: 'invalid padding mode',
  code: 'ERR_OSSL_RSA_INVALID_PADDING_MODE'
}

Removing the padding configuration gives an output for the encrypted password but the POST request return an internal server error.

curl -v --insecure --tlsv1.2 --tls-max 1.2 -H 'content-type: application/json' -d '{"ssid": "TestCast", "wpa_auth": 7, "wpa_cipher": 4, "enc_passwd": "KI1z4GA69ZLSYD6doPYi6c+gUXFOH/yKbfBlErxrP153OgaQCCf/KLXLxjlBc4iJr5sSw16KJS7OoBPCBgV9lirX5NU9W0hMxqwXE2oyT9vparTPh3vs0DoQOa35cNutLqm6oR/tEvbS28iCwZqfiGRXDPfdth0oNls1GfkcBdxvupRJWeBfazAJ+f+T+7on7ObnNaq+eaSsDEsuJIjtMYNaAtX4SnqF28tzSPs5XHnoF7Cv/1DSS5uRNNwOsXzrPdLyeR19ovHr8CbhNMYXAqqQ4QxPfAZqlp+BiZAn0XDtDvXuaQ6GN59FaF0kE7ClW+snWa6iFIMdRV3yyW8LEA=="}' https://192.168.41.68:8443/setup/connect_wifi

> POST /setup/connect_wifi HTTP/1.1
> Host: 192.168.41.68:8443
> User-Agent: curl/7.68.0
> Accept: */*
> content-type: application/json
> Content-Length: 414
>
< HTTP/1.1 500 Internal Server Error
< Access-Control-Allow-Headers:Content-Type
< Cache-Control:no-cache
< Content-Length:0
<

This is may be related to a nodejs version ? What was your nodejs to tested with ?

Regards,

[interfect]

@leo5593 I think this is related to a somewhat-nonsensical combination of cryptography options being specified: I would give a hash function to use for padding, and then specify a padding method that doesn't use a hash function.

I don't quite remember the Node version it worked on, but it clearly doesn't work on some Node versions and/or some versions of the backing system crypto libraries.

I've updated the gist as suggested in https://gist.github.com/interfect/5f68381d55658d334e2bc4619d796476?permalink_comment_id=4133830#gistcomment-4133830 to stop passing the hash function that shouldn't have been being used anyway. Maybe try it again now?

[lockness-Ko]

This still gives a 500 internal server error (even with bssid supplied). I'm doing some further testing to see if I can get more info. My thoughts is that it's not the node js implementation,